1. Field of the Invention
The present invention relates to an antitumor protein and an nucleotide sequence encoding the same.
2. Background Art
Various studies have been conducted on antitumor substances found in edible mushrooms.
For example, polysaccharides and glycoprotein from mushrooms which have antitumor activity are disclosed in Japanese Patent Laid-open Publication Nos.61214/1977, 74797/1980, 293923/1986, 70362/1993 and 80699/1994, Japanese Patent Publication Nos. 47518/1986, 47519/1986 and 26172/1991. It is also reported that mushrooms are found to have antitumor activity when administered.
However, there has been no report on an amino acid sequence of an antitumor protein derived from Tricholoma matsutake which directly kills a tumor cell and on a gene encoding said protein.
The inventors now have purified an antitumor protein derived from Tricholoma matsutake and determined an amino acid sequence as well as a cDNA sequence encoding the protein. Further, the inventors have successfully purified the cDNA sequence and obtained a recombinant antitumor protein expressed in E. coli which is transformed by introducing a vector comprising the cDNA sequence. The present invention is based on these findings.
Thus, an object of the present invention is to provide an antitumor protein, a fragment of said protein, a nucleotide molecule encoding said protein, a vector comprising said molecule, a host cell transformed by said vector, a process for preparing said protein, and an antibody against said protein.
The protein according to the present invention comprises
(a) an amino acid sequence of SEQ ID No.1, or
(b) a modified amino acid sequence of SEQ ID No.1 which has antitumor activity wherein one or more amino acids are added and/or inserted into the amino acid sequence of SEQ ID No.1 and/or one or more amino acids in the amino acid sequence of SEQ ID No.1 are substituted and/or deleted.
The protein according to the present invention is useful as an antitumor agent.